1. Field of the Invention
The present invention relates to an anti-weaving conveyor belt, and more particularly to an anti-weaving conveyor belt having at least one longitudinal guide member fixed to the back of the belt body to prevent the belt body from moving along in a zigzag course.
2. Description of the Prior Art
As is well known, a number of conveyor belts are used in factories or warehouses. These conveyor belts are used in transporting things from one place to another. Also, they are used in bringing and putting things such as works exactly at a given position. In this connection there has been a strong demand for preventing the belt from moving along in a zigzag course, thereby assuring that the belt moves straight. Some anti-weaving conveyor belts have been proposed and actually used. One example of such conventional anti-weaving conveyor belts uses a belt with perforations made at regular intervals along its opposite longitudinal edges, and main or auxiliary rolls having teeth to sequentially catch the perforations of the belt. No matter what material the belt may be made of, necessary perforations can be easily made. The perforations of the belt, however, are liable to be deformed or broken when the belt is subjected, for instance to strong vibration while being operated. Therefore, the linear movement of the conveyor belt cannot be assured for an extended period.
Another conventional anti-weaving conveyor belt uses a belt having guide strips along its opposite longitudinal edges, and main or auxiliary rolls each having a circumferential groove to allow each guide strip to fit in. The guide strips are fixed to the opposite longitudinal edges of the belt by using an adhesive. Therefore, the belt and the guide strips must be made of a material which is appropriate for sticking fast, such as rubber or polyurethane. A material which has a good releasability or mold release characteristic, cannot be used if it is not appropriate for sticking fast. Fluoroplastic belt and guide strips are made by impregnating heat resistant material molds with a fluoroplastic and then calcinating the same, and they are appropriate for being used in an atmosphere of elevated temperature. But, the fluoroplastic-impregnated guide strips can be hardly fixed to the fluoroplastic-impregnated belt by an adhesive. This makes it difficult to provide a conveyor belt which can be used in an atmosphere at an elevated temperature.
The guide strips are made by impregnating rubber or plastic mold with a fluoroplastic, and they will expand or contract evenly when subjected to external force. When the guide strip fits in the groove of the roll at each turning end, however, the part of the guide strip which is near the bottom of the groove of the roll will be curved more largely than the part of the guide strip which is remote from the bottom of the groove of the roll, and as a result, the rubber or plastic strip will be distorted in the roll groove to the extent that the belt cannot smoothly move.